Luria's (1970) goal as a neuropsychologist was to map out the brain's systems and functions responsible for complex behavioral processes, especially the high level processes associated with the intake and integration of information and with problem-solving abilities. Rather than formulating a one-to-one mapping of cerebral cortex functions, Luria perceived the brain's basic functions to be represented by three main blocks, or functional systems.

These three blocks are responsible for arousal and attention (Block 1); use of one's senses to analyze, code, and store information (Block 2); and the application of executive functions for formulating plans and programming behavior (Block 3). Block 1 functions correspond to the reticular activating system, and Block 3 functions are associated with the anterior portion of the frontal lobes. "Block 3 is very closely related to the functions of Block 1, since both blocks are concerned with overall efficiency of brain functions" (Reitan, 1988, p. 335). The intake and storage of information associated with Block 2 functions were believed by Luria to be specific to the senses involved in the coding of the information - primarily vision, hearing, touch, and kinesthesis - and located in the occipital, parietal, and temporal lobes behind the central (Rolandic) fissure. Within Block 2, Luria (19966b) distinguished between "two basic forms of integrative activity of the cerebral cortex" (p. 74), which he labeled successive and simultaneous.

Although Luria distinguished between the three blocks and their separate aspects of brain functions, his main emphasis was on the necessary integration of these blocks into functional systems that could support complete behavior. Part of the role of Block 2 I to establish "connections with the third block and effecting integration of incoming information through the various senses" (Reitan, 1988, p. 333). Indeed, as Reitan (1988) stressed about Luria's theory, "integration of these systems constitutes the real key to understanding how the brain mediates complex behavior" (p. 333). Naglieri (1999), similarly, has emphasized that the processes associated with the three blocks "are interdependently involved in activity and interact with the person's fund of knowledge" (p. 21).

Luria figure.pdf

Figure 2.1 summarizes the functions associated with each of Luria's three blocks. An abundance of empirical research supports Luria's (1966b, 1970, 1973, 1980) clinical documentation of the three functional units (see, for example, Das, Kirby, & Jarman, 1979; Das, Naglieri, & Kirby, 1994; Naglieri, 1999; Naglieri & Das, 1997). However, to apply his theory to the assessment of general cognitive and processing abilities, the authors believe that it is more important to focus on the integration of these blocks than on the specific measurement of each block. Indeed, Naglieri, Das, and their colleagues also emphasize the necessary integration of the three blocks for any kind of complex behavior.

The Block 1 arousal functions are key aspects of successful test performance on any cognitive task, but attention, concentration, and "regulating the energy level and tone of the cerebral cortex" (Reitan, 1988, p. 333), per se, do not fit the authors' definition of high-level, complex, intelligent behavior. Similarly, Luria (1966b) defines the Block 2 functions of analysis and storage of incoming stimuli via successive and simultaneous processing as "coding" functions, not problem-solving functions. The aspects of Block 2 that are of greatest interests of beyond the distinction between the two coding processes to include Luria's emphasis on the integration of the incoming stimuli and the responsibility of Block 2 for making connections with Block 3. Regarding the first point, the KABC-II includes subtests that require synthesis of auditory and visual stimuli, for example, Word Order, Atlantis, Rebus Learning, and Rover. Concerning the linkage between Blocks 2 and 3, the KABC-II includes measures of simultaneous processing g that not only require the analysis, coding, and storage of incoming stimuli, but also demand executive functioning and problem solving for success (e.g., Rover, Conceptual Thinking).

The key role of evaluating Block 3 executive functions on the KABC-II in accentuated by the extension of its age range to 18 years. Much neurological evidence supports the ages of 11 to 12 as crucial for the development of the prefrontal cortex, leading to the refinement of executive functions for solving every type of problem (Golden, 1981). Measurement of executive and planning functions in the primary-grade child, whose Block 3 abilities are emerging steadily but inconsistently, is extremely important; measurement of these same block 3 functions in the adolescent, following rapid prefrontal-lobe development, is absolutely vital.

But just as important as offering measurement of Block 2 and Block 3 functions on the KABC-II is evaluating the dynamic integration of the three blocks. As Luria (1970) stated, "It is clear that every complex form of behavior depends on the joint operation of several faculties located in different zones of the brain" (p. 68). That type of joint operation is especially crucial if children are to learn new material efficiently, and it is reflected in their scores on the Learning/Glr scale. The KABC-II learning tasks each demand Block 1's focused and selective attention while coding and storing complex auditory and visual stimuli simultaneously (Block 2) and generating strategies to learn the material efficiently (Block 3). Similarly, the KABC-II planning subtests require strong Block 1 attention skills to permit the child to generate hypotheses, make decisions, apply working memory effectively, and self-monitor behavior. However, the arousal functions associated with the limbic system and Block 1 were considered to have insufficient construct or content validity - by themselves - to fit into the authors' definition of general cognitive and processing abilities.

Reference

Kaufman, A., & Kaufman, N. (2004). Manual of the Kaufman Assessment Battery for
Children, 2nd. Edition. Pearson Assessments.